Screening and purifying machine



Oct. 15, 1940. D; M. s ALR SCREENING AND PURIFYING MACHINE Fild Oct,

12. n1. Ska/?" WITNKSS Patented Oct. 15, 1940 it i a I ITED srAfrEs PATIENT oF ICE i David M. Shaler, Leavenworth, Kans., assignor of I one-half to Jennie M. Shaler, Silver Creek, N. Y.

Application October 6, 1938; Serial No 233,668

5 Claims. (01. 209-28) I The invention relates primarily 'to mac hines It is the object ofvthe presentinvention to for screening and purifyingvv'arious kinds of fineprovide a. new: and improved construction which ly divided materials, and is particularlyadapted is free from such disadvantages as those above for use in the milling of flour and the like. Few pointed out and will operate efficiently with little 5 .improvements have been made in the fundamenattention, after initial adjustment according to 5 tal principles of sieve purifiers or screens in recent 'the'stock to be screened andpurified. years. The greater number of purifiers now in With the foregoing and minor objects inview, use which could be classed as the conventional the invention resides in the novel subject matter type, comprise a horizontal,reciprocating, screen hereinafter described and claimed, description with traveling hair brushes to clean the screen being accomplished byjreference to the accom-' 10 from the underside, an air chamber above the panying drawings.

screen, a superimposed suction fan connected to Figure 1 is a central vertical longitudinal secthe air chamber, a hopper-like compartment betion of the machine. I low the screen terminating in screw conveyors Figure 2 is a transverse sectional view on line close to the floor to transport the finished'mate- 2-2 of Fig. 1. U 15 rials from the machine, and a system of cut-off Figure 3 is an enlarged fragme y o al slides of fixed' width to direct the materials ,into View t ou h t e right h (a d 0f the machine. one conveyor or another. This type of construc- Figure 4: is a horizontal sectional view on line tion requires a considerable amount of space ,4 of'Figand moreover necessitates complicated transmi'sn thed ings above briefly described; a D 20 sion means for operating thebrushes and the ferr'ed construction has been illustrated, and conveyors. The amount of power required to op- While this construction will be rather specifically erate the machine is excessive compared to th e explained, it" iS tO be understood that Variations amount of Work accomplished. .In this type of may e made W t n t SCOPE t invntion machine, louvre doors are provided on the sides claimed. i 5

of the machine immediately below the screen to v A pp p pstanding frame [0 is proadmit air under said screen, but with such means Vided upp t PQ appropriate cushions I I. of. admitting the air, there is no way to control the ting on a floor 12, the upper Portion of d air toany particular section of the screen. The frame being p fl d i er n 3 'of sheet hopper-shaped sides 'of the chamber below the metal the like th p p e dOOIS "[30v screen become heavily coated with the material combing in forming a Su t o 0061 [5 in the uppassing through said screen and channels often per portion ofv d fra D tly under this form in this coating causing the finished product suction hood is a screen frame I6 which carries a to be diverted to the wrong conveyor, or in other l ty Screens ranging frOm re y fi e Words, causing a, crossing of the'finishe d stock. the h n of the a e to e vely The conveyors collect large quantities of "finished j the m n T thereof- In the Present product which in time become rancid and condisclosure, fiv Screens n l a taminated with moth webs, flour worms and S w each, screen being provided'with' an indilarvge, Thefeedbox i thi typeof machifle'i vidual' frame 22 resting upon suitable supporting 40 usuallyof'the shaker type and is located inside means 1, ar y m fr me a eld the machine housing in the air chamber. When r a t upward v nt by suitable making adjustments to the feed, it is necessary removable cleats or r Ob ously, any to open the d or at the he d d Of'th m h screen and its frame 22 maybe removed without and when so doing, the air purifying effect is urbing the others, for instance, to pp suspended and the machine as a whole does not Screen (310th Gi a WEB finer weal/6g as m y 45 function. In this type of machine, therefis no be q i d- I q aspirating effect applied to the stock before "the The main screen frameI-G is supported by inlatter is delivered to the screening means. The clined spring arms 25'secured attheir lower ends screen cleaningbrush generally travels from side to said frame and secured'at their upper ends to to sideand in the same path, and as a conseappropriate brackets 26 carriedby the frame I0 50 quence, excessive wear takes place and the screen The frame v I 6 is provided with'upwardly project cloth is often torn apart by the brush. "Moreover, 'ing plates 21 at its sides, connected by a transmoth webs often form in the brush structure de- 'verseshaft 28. The lower ends o'fpitman rods 29 stroying its efi'ectiveness and causlngcontaminaare' connected with the shaft 28 andthe upp'er tion. j ends of these rods are operatively"connectedwith f.

eccentrics on a transverse shaft 3| which may be driven in any preferred manner, for instance, by means of an electric motor 32 and a belt and pulley drive 33. The shaft 3| is mounted in appropriate bearings 34 carried by a transverse bar 35 forming part of the frame H1.

The top of the suction hood I5 is provided with an air outlet 36 for connection with a suction fan or conduit (not shown), and it will be seen that reduction of pressure in said hood will cause ascent of air currents through the various screens and the material thereon to purify this material. In order that this operation shall not be impaired by any air entering between the screen frame l6 and the lower end of the hood, suitable flexible curtains or the like 3'! connect said frame and hood without interfering with the vibration of the frame, produced by driving of the eccentrics 30.

A feeder 38 of the squirrel cage type is mounted upon the suction hood l5, and the rotary feed member 39 of said feeder may well be driven by a belt and pulley drive 40 from the shaft 3|. The feeder 38 is provided with a tubular discharge chute 4| which extends downwardly through the suction hood I5 and terminates slightly above a feed pan 42 which distributes the material upon the first screen H, the lower portion of said chute 4| being provided with a flap valve 43 urged toward closed position by a weighted arm 44 and opened only by the weight of the material resting upon it, said flap valve serving to prevent the entrance of any objectionable air currents with the ingoing material. Above the flap valve 43, one side of the chute 4| is provided with an air inlet 45 to which an air conduit 46 extends from the exterior of the hood I5, the outer end of said conduit being provided with a controlling valve or wicket 41. Opposite the air inlet 45, the chute 4| is provided with an air outlet 48 connected with a conduit 49 which, in the present disclosure, extends to a suction conduit 50 at the exterior of the hood l5, although said conduit 49 could be connected with the air outlet 36 of said hood, if desired. The suction created in the conduit 49, creates a current of air across the chute 4|, said air entering in one quantity or another according to the adjustment of the valve 41. This current of air passes through the material descending through the chute 4| and serves to initially purify the same before it is discharged onto the screen. To slow down the material somewhat and spread it out into a relatively thin vertical stream tobe more effectively acted upon by the air current across the chute 4|, this chute is preferably provided with an inclined baffle 5| directly above the air inlet 45 and outlet 48.

A receiving pan I2 extends longitudinally under the screen frame l6 and is suitably secured to this frame to vibrate therewith. This pan is provided with a plurality of receiving portions 53, 54, 55, 56 and 51, disposed under the screens l1, |8 |9, 20 and 2| respectively, each ofsaid receiving portions being provided with an individual material discharge spout 58 and with an individual air inlet 59. Suitably adjustable valves 66 are provided to control the air entering through the inlets 59, and this air ascends through the various screens and the material thereon, into the suction hood l5 from which it discharges at l6, again cleaning and purifying the material being screened. By relatively regulating the valves 60 as required, the strengths of the air currents flowing upwardly through the various screens, may be varied as desired, to produce the best results.

The chutes or spouts 58 are connected by flexible sleeves 6| with discharge chutes 52, and in the latter I provide flap valves 63 urged toward closed position by weighted arms 64 and opened only by the weight of the material resting upon them, said flap valves serving to prevent any appreciable upward flow of air through the material discharging from the machine. The tailings outlet 65 is also connected by a flexible sleeve 66 with a discharge chute 61 in which is a valve 68 identical with the valvese 63, preventing any appreciable amount of air from entering the suction hood |5 through said tailings outlet.

Each of the receiving portions 53 to 5! of the pan 52, is provided with an extensible plate 69 adjustable longitudinally of the machine, the

plate 69 of the receiving portion under any one of the screens being projectable partly under the next adjacent screen. Thus, if desired, part of the material which would ordinarily fall directly through this latter screen into the underlying receiving portion of the pan, will be diverted into. the next receiving portion, toward the tail end T of the machine. Thus, if the material passing through the screen I! should be found over-screened with the result that undesirably coarse particles are being received in the pan portion 53, the plate 69 of the next pan portion 54 would be adjusted to partly underlie said screen H, thus catching the relatively coarse particles passing through this screen and diverting them into the pan portion 54. Similar adjustments may, of course, be made with the plates 69 of the other pan portions so that only material of' the desired predetermined grades will be discharged through the spouts 58.

In the present disclosure, each of the receiving portions 53to 51 of the pan 52 is provided with a bottom 10, portions II of which decline to the spout 58. At the side of this spout toward the tail end of the machine, is a rather steeply inclined wall 12 which extends transversely of the pan 52 throughout the width of the latter. This wall (2 is preferably apertured to provide the air inlet 59. At the opposite side of the discharge spout, each receiving portion of the pan 52 is provided with another transverse wall 13 less steeply inclined, and in the present disclosure, the adjustable plate 69 is slidably mounted on this wall 13, being provided with any desired adjusting means 74. The various plates 69 may be adjusted to any required extent beyond the walls 12 so that they overhang the air inlets 59, and the'valves 60 are preferably so located as to be always beneath said plates 69. The receiving portion 51 need not be provided with a vertical wall such as 59, the air inlet 59 for this receiving portion may be located in the bottom thereof, and the valve 60 for this air inlet opening may be disposed above the latter. It will also be clear that the receiving portion 53 under the first screen I! is provided with no adjustable plate such as 69. I

In addition to providing the air admission means above described for the various receiving portions 53 to 51 of the pan 52, I preferably provide additional air inlets or wickets I5 in the opposite sides of said receiving portions and controllable in any suitable way.

In operation, the motor 32 drives the eccentric shaft 3| to vibrate the screen frame Hi and the receiving pan 52, also effecting rotation of the feeding member 39 of the squirrel cage feeder. 38. The material is fed by this rotary member tothe chutes 4|, in which it descendsto the feed pan 42,

encountering the crossdraft of air between the inlet 45 and outlet 48 during its travel and being thus subjected to an initial purifying operation.

The pan 42 distributes the materialevenly on the first screen I! and the movement of the screen .frame.is such as tofeed this materialtoward the the desired different grades, which grades are received in the various pan-portions 53to 51 and discharge through the spouts or the like 58 there of. Whenever desired, the plate 59 of any of these receivingportions of the pan 52, may be extended to a greater. or lesser extent so as to divert part of the screened, material passing through any of the screens, into the receiving portion of the pan under the next adjacent screen, permitting more accurate grading than otherwise possible. Moreover, the valves 60 maybe adjusted to control the upwardair-currents to obtain the best results from thesecurrents as they pass through the screens and the material thereon,.said currents and any dust and the like with whichthey are laden,entering the suction hood l5 andleaving through the outlet 36. The valves 80 are of course adjustable independently of the. valves or the like controllingthe additional air.inletsand all of thesevalves may be adjusted by any preferred or conventional means. I a r 4 The improved machine possesses numerous advantages over conventional machines such as those previously mentioned herein, The feeder 38, being of the squirrel cage type andmounted at the exterior of the suction hood I5, is ,readily accessible without admitting air to saidsuction hood or disturbing" the functioning of. the machine in any manner. The construction. associated with the discharge chute 4t of this feeder ,38, provides an effective aspirating system to remove a considerable amount of undesirable products from the 'material before it reaches the screening surfaces, thereforeincreasing theefiiciency of the machine. The quality of the flour produced from the purified middlings depends largely upon the amount of ash it contains, which ash originates from the fibrousmatter in the middlings. Therefore, keepinglthe' ash-forming substances from coming in contact with the screen surface is an'important advantage. As the stock or material received by the first screen is composite, containing all of the grades in its particular class,-it follows that the load is heavier upon this first screen and it is therefore very desirable to be able to have a greater upward air pressure or drop through the screen cloth at this point, than further toward the tail where the load is lighter and the material of a coarser' granulation. This regulation of theair is readily accomplished by the system of air valves above described. It is very important that the graduation of the screening surface be under fractional control the whole length of the screen, and to accomplish this, I have divided the screen surface into separate panels or sections and the receiving pan 52 into separate receiving portions or sections 53 to 57, with the slidable plates 69. tory pan 52 for conveying the separated material to the various discharge spouts, is a decided improvement over the screw conveyor system as it requires practically no power to operate and it will not crush any of the material. Moreover,

The 'vibranecessary. The screen vibrating means is on top .of the mainframe, saving length in the general machin e construction. ,Both withinand without, the machine is accessible for cleaning, repairing,

etc. As a whole, the machine is simple. in construction, requires small space, is of comparatively lightweight, substantially fire resisting, re-

quires few repair parts, requires only a relatively small amount of power for operation, and can be constructedat a saving over the conventional type;

The-general construction shown and described is preferable,;but attention is again invited to-the possibility of making variations within the scope of the invention as claimed.

What is claimed is; I, 1. ;A screening and purifying-machine comprisa, vibratory screen frame :having screens ranging from relatively-fine at thehead end of the machine to relatively coarseat the foot end thereof, a vibratory receiving pan underand covered by saidscreens, said 'pan having a plurality of receiving portionsdisposed under said'screens respectively, said receiving portionsrbeing'provided with individual discharge spouts and with lation with said screens, a feeder for feeding the material to be screened and purified onto, the finest of said screens, said feeder-beingconstructed to prevent any objectionable air, current fromv entering said suction hood with the ingoing material, means for exhausting air from said suction hood to cause air to entersaid air inletsandrascend through said screens and the -material thereon, valves for said air inletsto individually controlthestrengths ofxthe air curdischarge spout from the coarsest of. said screens, valve means'for -.preventing .'entrance of air to saidsuction hoodthrough' this spout, and valve means for preventing entrance of air tosaid receiving pan through the aforesaid discharge spouts thereof. l 2..'-A screening and purifying machin comprising a vibratory screen frame having screens ranging from relatively fine at the .head end of the machine to relatively coarse at the foot end thereof, a vibratory receiving pan under and covered by said screens, said pan having a plurality of receiving portions disposed under said screens respectively, said receiving portions being provided with individual discharge spouts and with individual air inlets, some of said receiving portions being provided with screened-material diverting means adjustable longitudinally of said pan, said diverting means of the receiving portion under any one screen being projectable partially under an adjacent screen to divert part of the material passing through thislatterscreen into said one receiving portion, means for simul- 3 being of the vibrating type, it will. not become contaminated with moth webs, larvae,-etc. More- .over, it is readilyaccessible should cleaning be rents ascendingthrough said screens, a tailings J taneously shaking said screen frame and receiving pan to sift the material through said screens and to shake it from said diverting means, a cas- F ing providing a suction hood over and in operative relation with said screens, a feeder for feedfrom entering said suction hood with the ingoing material, means for exhausting air from said suction hood to cause air to enter said air inlets and ascend through said screens and the material thereon, valves for said air inlets to individually control the strengths of the air currents ascending through said screens, a tailings discharge spout from the coarsest of said screens, valve means for preventing entrance of air to said suction hood through this spout, andvalve means for preventing entrance of air to said receiving pan through the aforesaid discharge spouts thereof.

3. A screening and purifying machine comprising a fixed upstanding frame structure having a downwardly open suction hood at its upper portion and extending throughout the width thereof, a vibratory screen frame supported within said frame structure under said hood and having screens ranging from relatively fine at the head end of the machine to relatively coarse at the tail end thereof, yieldable means supporting said screen frame within said fixed frame structure, flexible air-excluding means connecting said screen frame with the lower end of said suction hood, means mounted on said fixed frame and connected with said screen frame for vibrating the latter, a receiving pan within said fixed frame under said screen frame and secured to the latter for vibration therewith, said pan having receiving portions disposed under said screens respectively, said receiving portions being provided with individual discharge spouts and with individual air inlets, means for simultaneously shaking said screen frame and said receiving pan to sift the material through said screens and prevent it from piling on saidpan, a feeder for feeding the material to be screened and purified onto the finest of said screens, said feeder being constructed to prevent any objectionable air current from entering said suction hood with the ingoing material, means for exhausting air from said suction hood to cause air to enter said air inlets and ascend through said screens and the material thereon, valves for said air inlets to individually control the strengths, of the air currents ascending through said screens, a tailings discharge spout from the coarsest of said screens, valve means for preventing entrance of air to said suction hood through this spout, and valve means for preventing entrance of air to said receiving pan through the aforesaid discharge spouts thereof.

4. In a screening and purifying machine, a shallow receiving pan for screened material, said of the next receiving portion whereby said extension plate of any receiving portion will overhang said one wall of the nextreceiving portion, an adjustably mounted valve plate under each overhanging extension plate for controlling admission of air through the air inlet means of the adjacent wall, said valve plate extending substantially throughout the width of the receiving pan, being pivotally mounted at its upper edge substantially against the overhanging extension plate and being of a height to extend to the bottom of the pan when closed, and means for creating a current of air inwardly through said air inlet means and upwardly through said receiving pan.

5. In a screening and purifying machine, a vibratory screen frame having screens ranging from relatively fine at the head end of the machine to relatively coarse at the tail end thereof, a vibratory receiving pan under said screen frame and having receiving portions disposed under said screens respectively, said receiving portions being each provided with a bottom having a discharge opening and with walls extending trans-y.

versely of said pan at'opposite sides of said opening, one of 'saidwallsbeing provided with an air inlet, the other of said Walls being inclined and provided at its upper end with an inclined slidably mounted extension plate, this plate of the receiving portion under any one screen being projectable partly under an adjacent screen to divert part of the material passing through this latter screen into said one receiving portion, said walls of adjacent receiving portions being connected with each other at their upper edges, whereby the extension plate of any receiving portion projects beyond said one wall of the next adjacent receiving portion over the air inlet of the latter, and

DAVID M. SHALER. 

